A recent portable device has composite functions, such as photographing of photos or moving pictures, playback of music or moving picture files, game play, broadcasting reception service, support of a wireless Internet, and the like, and is implemented as an integrated multimedia player. Accordingly, the portable device has been developed to a new form in a hardware or software side in order to reinforce portability and convenience while satisfying a user's needs.
One of functions applied to the portable device is a function to control the portable device by using an electronic pen. An electronic pen of the related art is implemented to control the portable device by generating a touch or proximity input in the portable device or to control the portable device by operating a button included in the electronic pen.
However, a need for operation of the portable device according to various operations of the electronic pen has increased. Accordingly, a technical research and study to mount a wheel on the electronic pen has been carried out.
FIG. 1 is a circuitry diagram illustrating a configuration of a wheel circuit according to the related art.
Referring to FIG. 1, the wheel circuit according to the related art includes a switch where connection between ports is changed due to movement of an input unit. The switch may include a rotary encoder 110.
The rotary encoder includes three ports, that is, ports A, B, and C. As the rotary encoder is rotated, the port A can be electrically connected to the port B, or the port A can be electrically connected to the port C, or the port B can be electrically connected to the port C.
The port A and the port B are connected to two resistors R1 and R2 which have different resistance values, respectively, and the port C is grounded.
FIGS. 2A and 2B illustrate variation of signal output from port A and port B as a rotary encoder is rotated in a wheel circuit according to the related art.
Referring to FIG. 2A, it illustrates variation of signal output from the port A and the port B when the rotary encoder is rotated clockwise.
Referring to FIG. 2B, it illustrates variation of signal output from the port A and the port B when the rotary encoder is rotated counterclockwise.
The rotary encoder is rotated to change the electrically connected ports when power is applied to resistors R1 and R2. The electronic device including a wheel according to the related art may detect an operation state of the wheel based on output signal shown in FIGS. 2A and 2B.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.